SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea03dd5ab33b2e812d974bb1e33e3f592b2d70ed874e47fbc2bd0d5c0d01eaa1' 
  AND token = 'pji29G5JJJWtLWRd/DS216sPILnEKPnLyWbZjFPQiQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}